1. Field of the Invention
The present invention relates to a tab tape bonding apparatus which is used to bond semiconductor chips or single bumps to a tab tape.
2. Prior Art
Conventional tab tape bonding devices related to the present invention are disclosed in, for example, Japanese Patent Application Laid-Open (Kokai) Nos. 57-12529 (hereafter called "Conventional Device 1"), 54-116875 ("Conventional Device 2"), and 63-166238 ("Conventional Device 3").
Conventional Devices 1 and 2 are each equipped with (a) a loading section having a supply reel on which the tab tape is wound, (b) an unloading section provided with a take-up reel that takes up the tab tape after the completion of bonding, (c) a bonding device installed between the loading section and the unloading section so as to bond semiconductor chips to the tab tape, and (d) a tape feeder which intermittently feeds the tab tape wound on the supply reel to the bonding device and then to the take-reel at a predetermined pitch. The tape feeder is a means for driving a sprocket wheel which feeds the tab tape by engaging the teeth of the sprocket wheels with perforations formed in the tab tape.
In Conventional Device 3, the unloading section is a magazine. Accordingly, in order to cut the tab tape into card-form pieces of fixed dimensions after bonding, a cutter is employed. The cutter cuts the tab tape between the sprocket wheel driving means and the magazine. In addition, Conventional Device 3 is equipped with a roller driving means which acts as a tape feeding means so as to feed the cut-out card form pieces of tab tape into the magazine.
Thus, in the prior art, the tab tape wound on the supply reel is fed at fixed intervals to the bonding position of the bonding device by the sprocket wheel driving means so as to bond semiconductor chips to the tab tape.
In Conventional Devices 1 and 2, the tab tape is fed by the sprocket wheel driving means after bonding and then taken up on the take-up reel. In Conventional Device 3, the tab tape fed by the sprocket wheel driving means after bonding is cut into card-form pieces by the cutter, and then these card-form tab tape pieces are fed by the roller driving means and stored in the magazine.
Since the tab tape is fed by sprocket wheel driving means, the following problem arises: It is necessary to replace the sprocket wheels so as to meet with different pitches and shapes of perforations of the tab tape and with different tab tape widths. In other words, several sprocket wheels are necessary to handle various types of tab tapes which may be used.
Furthermore, since the tab tape is forcibly fed via sprocket wheels, the perforations may be damaged by the teeth of the sprocket wheels. Furthermore, the position in which the tab tape stops may vary erratically as a result of looseness [rattling] between the teeth of the sprocket wheels and the perforations. Thus, the precision with which the tab tape can be positioned tends to be poor.